[Hypothyroidism with leading myopathy in a patient suffering from systemic lupus erythematosus and Hashimoto's thyroiditis].
BACKGROUND
Muscle weakness with or without elevation of serum creatine kinase (CK) is a common complaint, which is a diagnostic challenge for the treating physician. Either infectious, neurologic, iatrogenic, genetic or endocrinologic and rheumatologic causes should be considered.


METHODS
A 66-year-old female patient with a history of systemic lupus erythematosus (SLE) currently in remission presented herself with muscle weakness, myalgias and elevated CK (1618 U/l) to the authors' hospital. A flare of the SLE as cause of the symptoms could be ruled out diagnostically. Instead, a Hashimoto's-associated hypothyroidism was detected. Treatment with L-thyroxine resulted in rapid improvement of symptoms, and CK levels returned to normal.


CONCLUSIONS
Although a myositis can be observed in SLE patients suffering from muscle weakness with elevated CK levels, a careful evaluation is warranted. In the presented case, hypothyroidism due to Hashimoto's thyroiditis was the real culprit of the symptoms.
Judex
Antonia
A
Klinik für Rheumatologie und Klinische Immunologie, Asklepios Klinikum, Bad Abbach, Germany. a.judex@asklepios.com
Hartung
Wolfgang
W
Schölmerich
Jürgen
J
Fleck
Martin
M
D000368:Aged; D003402:Creatine Kinase / Q000097:blood; D003937:Diagnosis, Differential; D005260:Female; D050031:Hashimoto Disease / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000175:diagnosis*; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000175:diagnosis*; D018908:Muscle Weakness / Q000209:etiology*; D013960:Thyroid Function Tests
D003402:Creatine Kinase